Internal-combustion motor.



C. S. SALFELD.

iNTERNAL COMBUSTION MOTOR.

APPLICATION FILED MAR. 23, I914.

1,262,850. Patented Apr. 16, 1918.

3 SHEETS-SHEET 1.

C. S. SALFELD.

INTERNAL COMBUSTIONMOTOR.

APPLICATION FILED mmzs, 1914.

1,262,850. Patnted Apr. 16, 1918.

3 SHEETS-SHEET 2.

C. S. SALFELD.

INTERNAL COMBUSTION MOTOR.

APPLICATION HLED MAR-23.1914.

Patented Apr. 16, 1918.

3 SHEETS-SHEET 3.

"IIII'IIIIIJIIZQ cmmnns s. amma), or MILWAUKEE, wrsconsnv.

v INTERN AL-COMBUSTION MOTOR.

Application filed March 23, 1914. Serial No. 826,472.

'To all whom it may concern:

Be it known that I, CHARLES S. SALFELD, a

' citizen of Germany, residing at Milwaukee,

der, instead of providing for the operation. of mechanically opened admission valves at tions.

county of Milwaukee, and State of Wisconsin, haveinvented new and useful Improvements in Internal-Combustion Motors, of which the following is a specification.

My invention relates to that class of internal combustion engines, in which a pre liminary compression of the air charge is secured preparatory to its delivery to the combustion chamber. 7

The primary object ofv my invention is to provide for an automatic pressure control of the delivery of compressed air to the cylinder, whereby the construction is not only simplified, but the air admission timed in correspondence with conditions in the cylinfi'xed intervals regardless of cylinder condi- A further object of'my invention is to improve the valve structures with a view to securing greater efiiciency and economy in operation.

In the drawings Figure 1 is a sectional view of an internal combustion motor embodying my invention,

drawn to a plane common to the axis of the cylinder, and of the air'inlet and exhaust v ducts.

Fig 2 is a similar view illustrating my invention in modified form.

Fig. 3 is a detail sectional view of a valve actuating device adapted to be used, either with the motor shown in Figrl, or with that shown in Fig. 2 for utilizing differences in pressure to operate a controlling valve.

Fi 4 is a detail sectional view of a modified orm of construction adapted to be sub-- stituted for the device shown in Fig 3.

Like parts are identified by the same reference characters throughout the. several views.

. 1 is a cylinder of a two cycle internal com bustion motor and 2 is a piston, the motion of which is transmitted in the usual manner to the crank 3 through a connecting rod 4. The piston 2 is of the ordinary cup shaped type, except that at its outer end it carries a larger piston 5, the latter serving to compress air on the return stroke in the annular chamber 6. During the expansion stroke of the piston 2, air is drawn nto the cavity 6 through a duct 7, the inner end of which is provided with a check valve 8. Air passing this check valve is received in a chamber 9 formed in or upon the outer wall of the cylinder and from which it passes through a port 10 to thechamber 6 between the inner and outer cylinder walls.

Duringthe compression stroke,the check valve 8 will of course be closed, a spring 12v being preferably employed to insure the ini-' tial closing of this valve. The compressed air will be expelled from chamber 6 (when the pressure becomes suificient), through a port 14, which is normally closed by a spring actuated check valve 15. This compressed air is received in a reservoir or air chamber 16, where it is stored for use in scavenging.

and charging cylinder 1. During the completion of the expansion stroke and the initial period of the compression stroke, air will be delivered from chamber 16 tothecylinder 1 through a duct 18 and the inlet port 19 of said cylinder. Acheck valve is employed to prevent an out-flow of burnt gases from cylinder 1 into the duct 18 during the expansion stroke. In Fig. 1 this valve isillustrated as a check valve 20 composed of'a flap of flexible material, having sufficient resilience to initially close fromopen position when the pressure in cylinder 1 and duct 18 are e ualized. In Fig. 2 delivery through the in ct port of cylinder 1 is controlled by a rotary valve presently to be described.

- But in either case it will be understood that the valve opens automatically for delivery of air and closes when the; pressure in the cylinder 1'exceeds that in duct 18 during the expansion stroke. the completion of the expansion stroke through a port 22 into cavity 23 with which exhaust duct 24 communicates. Ducts 26 and 27 pertain to the circulatory system connected with the water jacket cavities 28.

It will be observed that the port 19 is longer than the port 22, both grts, however, being so located that they wi each be fully open when the piston 2 com letes the expan- S1011 stroke. Port 19 will t erefore be partially opened before the piston uncovers any portion of-iport 22. But during the ex sion stroke, valve 20 will of course be 1 Specification of Letters Patent. Patgmted Apr. 16, 1918 I v Cylinder 1 exhausts at -7. During this stroke, check valves closed under the pressure of the expanding gases in cylinder 1 until the exhaust port 22 is uncovered, thus preventing the burned gases from entering the duct 18. As soon as port 22 is uncovered, such gases will be de-' livered into the exhaust duct 24, thus relieving the pressure in the combustion chamber. whereupon the pressure of air in duct 18 will open valve and fresh air will rush in to scavenge the cylinder. The initial compression movement of piston 2 will then first close the exhaust port 22, while port 19 is still partially open. At this moment, the combustion chamber will be filled with fresh air at a pressure somewhat in excess of atmospherie pressure but less than the full pressure of the air in chamber 16. But port 19 is elongated sufficiently to permit the pressure to substantially equalize on opposite sides of valve 20 before the piston closes port 19, and the cylinder, or the combustion chamber thereof, is therefore charged with air at substantially the full pressure of the air in chamber 16. The means for carbureting the air is not material, as this forms no part of the invention herein claimed. Hydro-carbon fuel may be delivered through an injector 17.

Briefly reviewing the operation of the construction illustrated in Fig. 1, it will "be understood that the outward movement of j the piston constitutes the suction stroke for chamber 6 and the expansion stroke for the combustion chamber. The inward stroke of the piston constitutes the compression stroke for both chambers. During the outward or suction stroke for chamber 6, inlet valve 8 will be opened, air being admitted more or less freely to chamber 6 in accordance with the positionof the throttle valve in duct 15 and 20 will both be closed, since the pressure in chamber 16 is then greater than in chamber 6 where a partial vacuum is being formed, and the pressure in the combustion chamber is greater than that in duct 18 owing to the expansion of the gases in the combustion chamber during combustion. At the completion of this stroke, valve 8 will be closed by spring 12,as soon as the pressure in chamber 6 is substantially equal to the atmospheric pressure, and during the compression stroke, valve 15 will open as soon as the pressure in chamber 6 exceeds that in chamber 16.

Valve 20, as previously explained, is forced open by the pressure in chamber 16 and duct 18 as soon as the expanding gases are permitted to exhaust through exhaust port 22.

Modified structure of F z'g. 2..

In Fig. 2 the air inlet ports 10 are uncovered only when the piston 5 is substane tially at the outer limit of its stroke. A nort 14 is provided for delivery of air from naeaeeo chamber 6 into the storage or compressed air chamber 16. This port is normally closed I by a spring actuated valve 15 like that shown ing the initial compressing movement, afterwhlch continued compression in chamber 6 is utilized to force air through a port and past a spring actuated check valve 36 into a duct 37, leading to valve chamber 38, from which this air may be delivered to the cylinder through a port 39. Air from chamber 16 may also pass to valve chamber 38 through a duct 18*, similar to the duct 18 shown in Fig. I, but which in this case need not be as large as said duct 18. The air delivered through the duct 18 may pass to the combustion chamber through a port 19?, provided for that purpose. But this only occurs when piston 2 is substantially at the outer limit of its stroke with said port 19 uncovered. A rotary valve 42 controls the delivery of air through duct 37. This valve is adapted in one posit-ion of adjustment to cut ofi' delivery to the valve chamber 38 through port 47 and simultaneously permit a delivery of such air through port 43 into a duct 44 which may convey it to another reservoir 41. A valve 45 is located in the cavity 38, said cavity being cylindrical. Valve 45 is of the Corliss type adapted to be adjusted to cut off air admission from duct 37 through port 47, and also to cut off air delivery through port 39. The valve 45 divides cham ber 38 into two compartments, one for the supercharging air and the other for the scavenging air entering from duct 18*.

The operation of the structure shown in Fig. 2 is similar to that shown in Fig. 1 with the exception that on the compression stroke of the pistons, the air in chamber 6 will first be forced into chamber 16, from which a scavenging air charge is delivered to the combustion chamber through duct 18 and port 19 It will be observed that port 19 is shorter than the exhaust port 22, and so located that the gases of combustion will first be permitted to exhaust and then fresh air will be permitted to enter through port 19 as the piston uncovers this port. The pressure in chamber 16 of Fig. 2 will of course be lower than the pressure in chamber 16 of Fig. 1, but it Wlll be suflicient for scavenging purposes. While the piston is moving on its compression stroke to close the scavenging port 19 and exhaust port 22, the valve 45 will be adjusted by the means hereinafter explained, to admit air from the compression or supercharging duct 37 and allow it to pass through ports 47 and 39 to the combustion chamber, thus filling said chamber with air under a higher pressure.

To operate the valve 45 automatically in response to pressure variations incident to the above describedoperation, I connect the controlling cylinder 48 shown in Fig. 3, to

the duct 18. When the motor is in operation and port 19 closed, the pressure in this duct will be suflicient to actuate a piston 49 in cylinder 48 in opposition to a spring 50 located between said piston and the cylinder head 51. The motion of this piston is transmitted through connecting rod 52 and arm 53 to the valve spindle 46 of'valve45, thereby adjusting the valve to the position in which it is shown in Fig.2. But as soon as port 19 is uncovered by piston 2, the pressure induct 18 will drop, owing to the delivery of the scavenging charge to the combustion chamber. This will of course cause a drop in pressure in the valve controlling cylinder 48, whereupon spring 50 will'push piston 49 backwardly, and thls motion will be transmitted to rotate valve 45 to theposition indicated by dotted lines in Fig. 2, uncovering port 39 and the inlet port 4701? the valve chamber through which air then enters from duct 37, whereupon the supercharge will be delivered to the combustion chamber. This position of the valve will, however, be

' momentary, for as soon as port 19* is closed by the piston, the'pressure in duct 18 will be built up from reservoir 16, and piston 49 will then again be actuated against the tension of. spring 50 to readjust valve to the position shown in Fig. 2; v The drop in pressure in duct 18 when port 19 is open, may

' ton 5, as it moves on the compression stroke to refill chamber 16.

. Valve 45 may be substituted 'for check: valve 20 in the structure shown in Fig. 1. In such case, however, its operation will depend upon changes in pressure in'the combustion chamber 1, and not upon. changes in pressure iii the duct 18. The cylinder 48 will" therefore be connected with a port 60', which will be pluggedwhen not thus in use. When cylinder 48 is so connected and used to operate the va1ve'45 in the structure shown in Fig. 1, it is obvious that said valve 45, may be closed at,all times excepting during the interval when the pressure in the combustion chamber is reduced by .the opening of the exhaust port 22, at which time the valve 45 will move to open position and remain open until the pressure in the combustion ressure sufiicient to actuate piston 49..

chamber is sufficiently built up on the compression stroke to actuate piston 49 in opposition to spring 50. a

Modified stmctwre of Fi 4. Fig. 4 shows a substitute for the valve mechanism illustrated in Fig. 3. Diiferen-' tial pistons 60 and 61- are connected to operate in the cylinders 62' and 63, which are also connected, end to end, as shown. Cylinder 63 may be connected at 64 with the scavenging air duct 18 of Fig. 2, and cylinder 62 may be connected with the supercharging duct 37. The pistons are so proportioned in,

area that the lowerv pressure of the scavenging air upon the larger piston will more .than balance thehigher pressure of the supercharging air upon the smaller pistonarea of piston 61. These pistons operate also as slide valves controlling ports 65, 66, 67, 68 and 69 respectively, the pistons being suitably ported. at 70. and 71..

In this construction the ports and 66 may lead to the combustion chamber and deliver air thereto for scavenging purposes,

these portsperforming the function of the port 19 in Fig. 2 or may le'adthrough the port 19 to the cbmbustion chamber if de-' sired. The ports 67, 68' and 69 may correspend in function with the supercharging port 39 in Fig.2.

In the operation of the piston valve, it will be understood that when the valve is in the position shown in Fig. 4, it will be subject to the full pressure of the scavenging air and the supercharging air and will tend to remain in such position. But when the piston 2 uncovers ,the'scav'enging port 19 (or- .ports 65' and 66.),the' pressure will be re lieved upon piston 61, whereupon'the pressure ofthe super-charging air upon piston 60 will movethe pistonsto the right, closing.

ports 65and 66 and opening ports 67, 68 and 69. The piston valves will remain in this position until the pressure of the scavenging air 'upon'piston 61 is again built up,

its.

whereupon the piston valves will returnto the osition indicated in Fig. 4.

Vi here air is to be pumped for purposes other than motor operation, the relative size of piston 5 may be varied in accordance with the requirements. By increasing the diameter of air chamber 6 and compressor piston.

5 beyond the requirements of the motor for scavenging and cylinder filling purposes,the device is converted into a combined motor and air compressor adapted to supply air for' commercial purposes.

I a r 1. A two cycle internalucombustion motor provided with a combustion chamber, hav-- ing inlet and exhaust ports adapted to be uncovered by the piston during its outward movement, a driving piston in said chamber,

a compressing chamber, a fluid compressing piston therein connected to move in synchronism with the driving piston, a reservoir adapted to receive fluid from the compression chamber, a valve adapted to prevent return of such fluid to the compression chamber, a duct leading from said reservoir to the combustion chamber, and communicating therewith during, and subsequently to the period of delivery through the exhaust port, a valve controlling the delivery of fluid from said duct to the combustion chamber, and fluid controlled means for automatically actuating said valve in one direction as pressure in the duct increases, together with means for automatically reversing the position of said valve when relieved from fluid pressure control.

2. A two cycle internal combustion motor provided with a combustion chamber, having inlet and exhaust ports adapted to be uncovered by the piston during its outward movement, driving piston in said chamber, a compressing chamber, a fluid compressing pistontherein connected to move in synchronism with the driving piston, a reservoir, adapted to receive fluid from the com-v pression chamber, a valve adapted to prevent return of such fluid to the compression chamber, a duct leading from said reservoir to the combustion chamber, and communicating therewith during, nd subsequently to the period of delivery through the exhaust port, a valve controlling the delivery of fluid from said duct to the combustion chamber, and fluid controlled means for automatically actuating said valve in one direction as pressure in the duct increases, said compressing piston having a greater area of compressing surface than the driving piston.

3. A two cycle internal combustion motor provided with a combustion chamber, having inlet and exhaust ports adapted to be uncovered by'the piston during its outward movement, a driving piston in said chamber,

a a compressing chamber, a fluid compressing piston therein connected to move in synchronism with the driving piston, a reservoir adapted to receive fluid from the compression chamber, a valve adapted to prevent return of such fluid to the compression chamber, a duct leading from said reservoir to the combustion chamber, and communicating therewith during, and subsequently to the period of delivery through the exhaust port, a valve controlling the delivery of fluid from said duct to the combustion cham- 'ber, and fluid controlled means for automatically actuating said valve in one direc-- tion as pressure in the duct increases, together-with an auxiliary reservoir adapted to receive a portion of the compressed fluid.

4. An internal combustion motor comprising the combination of combustion and comnaeaseo pression chambers provided respectively with motor and compression pistons, said compression chamber being'provided with outlet passages, one communicating with the combustion chamber in the annular zone of the exhaust port, and the other with said chamber between the first mentioned port and the cylinder head, and a valve dapted to open said ports successively.

5. An internal combustion motor comprising the combination of combustion and compression chambers provided respectively with motor and compression pistons, said compression chamber being provided with a plurality of outlets, one leading to the combustion chamber in the annular zone of the exhaust port, and the other to said chamber between the first mentioned outlet and the cylinder head, said outlets including suitable storage chambers for air under pressure and valve mechanism controlling delivery therefrom to the combustion chamber, together with separate means for delivering hydro-carbon to the combustion chamber.

6. An internal combustion motor comprising the combination of combustion and compression chambers provided respectively with motor and compression pistons, said compression chamber being provided with 7 An internal combustion motor comprising the combination of combustion and compression chambers provided respectively with motor and compression pistons, said compression chamber being provided with a plurality of outlets, one leading to the combustion chamber in the annular zone of the exhaust port, and the other to said chamber between the first mentioned outlet and the cylinder head, in combination with valve mechanism controlling delivery through said outlets to the combustion chamber, an auxiliary reservoir, valve mechanism controlling diversion of compressed air irom one of the outlet passages to said reservoir, and separate means for delivering combustible fluid thereto.

8. An internal combustion motor comprising the combination of combustion and compression chambers provided respectively with motor and compression pistons, said compression chamber being provided with a plurality of outlets, one leading to the combustion chamber in the annular zone of the exhaust port, and the other to said chamber between the first mentioned outlet and from the other compression chamber outlet i I the cylinder head, both of said outlets being maybe diverted. I 1% independent of fuel delivery, in combination In testimony whereof I aifix my signature with valve mechanism controlling delivery in the presence of two witnesses.

5 through said outlets to the combustion'cham- CHARLES S. SALFELD. ber, 'a reservoir interposed between one of Witnesses: said outlets and the combustion chamber, Lnvnnrr'r 0. WHEELER;

and an aumhary reservoir into which air IRMA D. Bnnm. 

